Hydrogen sulfide plays a role in the development of hepatopulmonary syndrome

Chinmay Bera, (2014) Hydrogen sulfide plays a role in the development of hepatopulmonary syndrome. Masters thesis, Christian Medical College, Vellore.

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Abstract

BACKGROUND & AIM OF THE STUDY: Hepatopulmonary syndrome (HPS) is an important pulmonary complication of cirrhosis and portal hypertension, characterized by intrapulmonary vasodilatation (IPVD) leading to impaired oxygenation. Prevalence of this syndrome varied from 5 to 30% in different studies. Hydrogen sulfide (H2S), which is generated by vascular smooth muscle cells and liver by enzyme cystathione γ-lyase, has vasodilatory effect. Current study aimed at determining the prevalence of clinical and subclinical HPS in cryptogenic cirrhosis and establishing the role of H2S in pathogenesis of HPS. METHODS: During the period of January 2012 to November 2013, consecutive patients with cryptogenic cirrhosis were enrolled after a written informed consent. Diagnosis of cirrhosis was made by history, liver function abnormalities, endoscopy and abdominal ultrasonography. Chest x-ray, arterial blood gas analysis (ABG) and contrast echocardiography (CE) was done in all patients. HPS was diagnosed in a patient if extra-cardiac shunting demonstrated by contrast echocardiography (positive CE) was accompanied by hypoxemia (either PaO2 ≤80 mmHg or P(A-a) O2 >15 mm Hg or both). Diagnosis of subclinical HPS was made in patients with positive CE but absence of hyp7xemia. On the basis of ABG and CE findings patients were grouped into - no HPS (both are normal), subclinical HPS (normal ABG and CE positive), and HPS (both positive). Plasma H2S was measured by colorimetric method. RESULTS: 58 patients with cryptogenic cirrhosis (M: F:: 45:13; age 45 (16-74) years; median (range); Child’s Class A:30; B:18; C:10) were included in this study. Of the 58 patients, 34 (60%) had an extra-cardiac shunt on contrast echocardiography (positive CE). 13 of these 34 patients had hypoxia. Thus, 13 (21%) patients had HPS and 21 (40%) patients had subclinical HPS. Plasma H2S was measured in 47 patients (HPS:8; subclinical HPS: 20; No HPS: 19). Plasma H2S level was higher in patients with positive CE (19.5, 6.4-64.3 μmol/L; median, range) as compared to patients with no HPS (16.4, 0-83 μmol/L; p-value: 0.03). This difference remained significant despite adjusting for MELD score. Plasma H2S levels in patients with IPVD (19.6, 5.7-83 μmol/L) was higher than patients without IPVD (12.3, 0-47). CONCLUSION: 22% patients with cryptogenic cirrhosis had HPS. Plasma H2S, independent of severity of liver disease, was higher in patients with intrapulmonary vasodilation, suggesting a possible role of H2S in the pathogenesis of HPS.

Item Type: Thesis (Masters)
Additional Information: Reg.No.16115601
Uncontrolled Keywords: Hepatopulmonary syndrome, Hydrogen sulphide, Intrapulmonary vasodilatation, Contrast echocardiography, Arterial blood gas analysis.
Subjects: MEDICAL > Hepatology
Depositing User: Kambaraman B
Date Deposited: 13 Jan 2020 10:25
Last Modified: 13 Jan 2020 10:31
URI: http://repository-tnmgrmu.ac.in/id/eprint/11818

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